1. Field of the Invention
The present invention relates to cable glands and more particularly, to a cable gland and gasket ring assembly, which effectively prohibits access of dust and water particles to the inside of the junction box after installation of a cable with the cable bland in the junction box.
2. Description of the Related Art
After installation of a cable in a junction box by means of a cable gland, the cable may be disconnected or loosened from the connector or gland when stretched accidentally by an external force, causing leakage. To avoid this problem, an improved design of cable gland is disclosed. This prior art design of cable gland comprises a first shell, a packing ring, a sealing nut, a lock nut, a connection ring, an inner retaining ring, an elastic ring and a second shell. After installation, the packing ring is forced to wrap about the cable tightly, thereby locking the cable and protecting against moisture.
The water seal ring used in the aforesaid prior art cable gland is simply a rubber O-ring or rubber pad. When the rubber O-ring or rubber pad is sandwiched between the cable gland and the junction box of the signal source or signal receiver, it tends to be stretched or excessively deformed, leading in insufficient leakage protection.
Further, because the rubber O-ring or rubber pad has two opposite sides thereof respectively stopped against a planar wall surface at the junction box and a planar wall surface at the cable gland, a big number of dust particles and water particles may fall from the surfaces of the rubber O-ring or rubber pad, the cable gland and the junction box to the inside of the junction box to erode the internal circuit structure of the junction box.
Further, if the applied rotary force surpasses the pressure-bearing threshold of the rubber O-ring or rubber pad when fastening the cable gland to the junction box through a rotary motion, the rubber O-ring or rubber pad may be forced out of position, causing leakage.
Further, before installation of the cable gland in a junction box or during delivery of the cable gland, the rubber O-ring or rubber pad may fall from the cable gland accidentally.
Therefore, it is desirable to provide a gasket ring for cable gland, which eliminates the aforesaid problems.